Alternating relays for extended life of relays

Abstract

A system and method for including a processor having addressable memory, the processor in communication with two or more relays, where the processor is configured to: store a first state based on an order of two or more relays to be switched on; send one or more first signals to switch on a relay of two or more relays based on the stored first state; wait for a set time after sending each first signal of the one or more first signals; and update the first state based on the order the one or more first signals were sent.

What is claimed is: 
     
         1 . A system comprising:
 a processor having addressable memory, the processor in communication with two or more relays, wherein the processor is configured to:
 store a first state based on an order of two or more relays to be switched on; 
 send one or more first signals to switch on a relay of two or more relays based on the stored first state; 
 wait for a set time after sending each first signal of the one or more first signals; and 
 update the first state based on the order the one or more first signals were sent. 
   
     
     
         2 . The system of  claim 1 , wherein the processor is further configured to:
 store a second state based on an order of two or more relays to be switched off;   send one or more second signals to switch off a relay of two or more relays based on the stored second state;   wait for a set time after sending each second signal of the one or more second signals; and   update the second state based on the order the one or more second signals were sent.   
     
     
         3 . The system of  claim 1 , wherein the set time is greater than an operating time of each relay of the two or more relays. 
     
     
         3 . The system of  claim 1 , wherein the set time is based on a transfer time of the two or more relays and a system power cycle time. 
     
     
         4 . The system of  claim 1 , wherein the order of the two or more relays to be switched on is in a variable sequence determined by the first state. 
     
     
         5 . The system of  claim 1 , wherein the two or more relays are in an electric vehicle supply equipment (EVSE). 
     
     
         6 . The system of  claim 1 , wherein the processor is further configured to:
 check a status of the two or more relays after the one or more first signals were sent.   
     
     
         7 . The system of  claim 1 , wherein the stored first state is configured to vary which relay of the two or more relays is turned on as a first relay to be turned on, and wherein the stored first state is configured to reduce early degradation of a relay of the two or more relays in relation to other relays of the two or more relays. 
     
     
         8 . The system of  claim 1 , wherein the two or more relays comprise two relays, wherein a first first signal of the one or more first signals is configured to turn on a first relay of the two or more relays based on the stored first state, wherein a second first signal of the one or more first signals is configured to turn on a second relay of the two or more relays based on the stored first state. 
     
     
         9 . The system of  claim 8 , wherein the first first signal of the one or more first signals is configured to turn on the second relay of the two or more relays based on the updated first state, and wherein the second first signal of the one or more first signals is configured to turn on the first relay of the two or more relays based on the updated first state. 
     
     
         10 . A system for controlling a plurality of electrical switches, each electrical switch having two or more operational states and responsive to control signals for changing between operational states, the system comprising:
 a controller configured to generate control signals to selectively change the operational state of one or more of the electrical switches based on at least one of: a selected timing and a selected sequence;   wherein the selective changing of the operational state of the one or more of the electrical switches is configured to reduce early degradation of the one or more of the electrical switches in relation to said plurality of electrical switches.   
     
     
         11 . The system of  claim 10 , wherein the controller is further configured to generate control signals to selectively change the operational state of one or more of the electrical switches based on a selected timing as a function of the operational characteristics of one or more of the electrical switches. 
     
     
         12 . The system of  claim 11 , wherein the controller is further configured to selectively change the operational state of one or more of the electrical switches based on a selected timing as a function of said operational characteristics including one or more of: power cycle time and switch transfer time. 
     
     
         13 . The system of  claim 10 , wherein the controller is further configured to generate control signals to selectively change the operational state of one or more of the electrical switches in a variable sequence. 
     
     
         14 . The system of  claim 13 , wherein the controller is further configured to generate control signals to selectively change the operational state of one or more of the electrical switches in a variable sequence based on selected timing as a function of one or more of: power cycle time and switch transfer time. 
     
     
         15 . The system of  claim 10 , wherein the controller is configured to generate control signals to change the operational state of one or more of the electrical switches in an alternating sequence. 
     
     
         16 . The system of  claim 15 , wherein the controller is further configured to change the operational state of one or more of the electrical switches in an alternating sequence based on selected timing as a function of one or more of: switch transfer time and system power cycle time. 
     
     
         17 . The system of  claim 10 , wherein the controller is further configured to change the operational state of each of the electrical switches based on a selected timing and selected sequence to prevent one or more of the electrical switches from early degradation in relation to the other electrical switches in the system. 
     
     
         18 . A system comprising:
 a plurality of electrical switches, each electrical switch having two or more operational states and responsive to control signals for changing between operational states;   a controller configured to generate control signals to selectively change the operational state of one or more of the electrical switches based on at least one of: a selected timing and a selected sequence,   to reduce early degradation of one or more of the electrical switches in relation to said plurality of electrical switches.   
     
     
         19 . The system of  claim 18 , further comprising:
 N relays;   a state counter C that cycles through counts 1, 2, . . . , N, 1, 2, . . . , N, 1, 2, . . . , N,   wherein the controller is further configured such that in a power cycle:
 in a control state C, upon receiving a power on signal, a relay C is turned on first, and then subsequent relays are turned on in sequence after a set wait time has passed for each delay; 
 in the control state C, upon receiving a power off signal, relay C is turned off first, and then subsequent relays are turned off in sequence after a set wait time has passed for each; 
 the state counter is incremented by one, such that when C=N, the state counter C is reset to 1. 
   
     
     
         20 . The system of  claim 19 , wherein the set wait time is a function of at least one of: relay transfer time and system power cycle time.